It is common practice in the mounting of semiconductor chips to connect the semiconductor chips, mainly power semiconductors, to the substrate by means of solder in order to ensure via the solder connection an effective dissipation of the heat loss from the semiconductor chip that occurs during operation. However, also other “dies” are soldered onto the substrate.
Metallic substrates, so-called leadframes, are mainly used as substrates, where the semiconductor chips are soldered onto chip islands arranged one after the other and optionally next to one another. Single-place substrates, which are also known as so-called singulated substrates, are also used. Such a single-place substrate consists of a ceramic platelet for example, which is covered on both sides by a metal layer. The substrates are usually supplied in cycles to a soldering station where the solder is applied, a distributing station where the solder is distributed on the substrate location, and then to a bonding station where the semiconductor chips are placed by means of a pick-and-place system on the liquid solder portions. The leadframes comprise holes arranged along their longitudinal edges, into which pins or fingers engage for the transport of the leadframes. A die bonder which is suitable for this process is marketed by the applicant under the name DB2009 SSI. This die bonder comprises a through-type furnace which is formed as a channel or tunnel, through which the substrates are transported to the soldering station, distributing station and bonding station. The forward feed of the substrates occurs by means of fingers which are provided with teeth, can be lifted and lowered, and moved back and forth, wherein each finger moves a substrate in the forward direction.